/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.ssi;

import org.apache.catalina.util.Strftime;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Locale;

/**
 * Implements the Server-side #flastmod command
 *
 * @author Bip Thelin
 * @author Paul Speed
 * @author Dan Sandberg
 * @author David Becker
 */
public final class SSIFlastmod implements SSICommand {
	/**
	 * @see SSICommand
	 */
	@Override
	public long process(SSIMediator ssiMediator, String commandName,
	                    String[] paramNames, String[] paramValues, PrintWriter writer) {
		long lastModified = 0;
		String configErrMsg = ssiMediator.getConfigErrMsg();
		for (int i = 0; i < paramNames.length; i++) {
			String paramName = paramNames[i];
			String paramValue = paramValues[i];
			String substitutedValue = ssiMediator
					.substituteVariables(paramValue);
			try {
				if (paramName.equalsIgnoreCase("file")
						|| paramName.equalsIgnoreCase("virtual")) {
					boolean virtual = paramName.equalsIgnoreCase("virtual");
					lastModified = ssiMediator.getFileLastModified(
							substitutedValue, virtual);
					Date date = new Date(lastModified);
					String configTimeFmt = ssiMediator.getConfigTimeFmt();
					writer.write(formatDate(date, configTimeFmt));
				} else {
					ssiMediator.log("#flastmod--Invalid attribute: "
							+ paramName);
					writer.write(configErrMsg);
				}
			} catch (IOException e) {
				ssiMediator.log(
						"#flastmod--Couldn't get last modified for file: "
								+ substitutedValue, e);
				writer.write(configErrMsg);
			}
		}
		return lastModified;
	}

	protected String formatDate(Date date, String configTimeFmt) {
		Strftime strftime = new Strftime(configTimeFmt, Locale.US);
		return strftime.format(date);
	}
}